Improved I-V characteristics of SiC MOSFETs by TCE thermal gate oxidation

The effects of TCE (trichloroethylene) thermal gate oxidation on the electrical characteristics of SiC MOSFETs are investigated. It is found that TCE thermal gate oxidation can improve the I d-V d characteristics, increase the field-effect mobility, and reduce the threshold voltage and sub-threshold slope of the devices. The better device characteristics are believed to be attributed to the TCE-induced reductions of charges in the gate oxide and traps at the SiO/SiO 2 interface, and also to the gettering of charged impurities and reduction of physical defects by the chlorine incorporated in the gate oxide. ©2005 IEEE.published_or_final_versio

ADVISE: Symbolism and External Knowledge for Decoding Advertisements

In order to convey the most content in their limited space, advertisements embed references to outside knowledge via symbolism. For example, a motorcycle stands for adventure (a positive property the ad wants associated with the product being sold), and a gun stands for danger (a negative property to dissuade viewers from undesirable behaviors). We show how to use symbolic references to better understand the meaning of an ad. We further show how anchoring ad understanding in general-purpose object recognition and image captioning improves results. We formulate the ad understanding task as matching the ad image to human-generated statements that describe the action that the ad prompts, and the rationale it provides for taking this action. Our proposed method outperforms the state of the art on this task, and on an alternative formulation of question-answering on ads. We show additional applications of our learned representations for matching ads to slogans, and clustering ads according to their topic, without extra training.Comment: To appear, Proceedings of the European Conference on Computer Vision (ECCV

Crop straw incorporation interacts with N fertilizer on N₂O emissions in an intensively cropped farmland

Nitrogen (N) fertilization and straw incorporation strongly influence nitrous oxide (N2O) emissions from agricultural fields. An in-situ micro-plot experiment on intensively farmed winter wheat (Triticum aestivum L.) was conducted to investigate the source and rate of N2O emissions from soils following labeled 15N fertilization with and without straw incorporation. Four treatments, i.e., no N fertilizer and no straw incorporation (N0S0), straw incorporation only (N0S1), N fertilizer only (N1S0), and N fertilization plus straw incorporation (N1S1), were established in the experiment. The N2O emissions mainly occurred after N fertilization and lasted for approximately 1–2 weeks, accounting for 60%–67% of the wheat seasonal N2O emissions. Within the 6 days after basal fertilization and 2–4 days after top-dressing, most of the N2O fluxes (>50%) were derived from fertilizer. Thereafter, soil-derived N2O dominated the total N2O emissions and within 10–20 days after N fertilization, fertilizer-derived N2O became negligible. Fertilizer N and soil N both accounted for 40%–60% of the seasonal N2O emissions, which may be explained by the high soil N stock due to long-term high N fertilization in the region. This implies the similar roles of soil N pool and fertilizer N in N2O generation under intensively farmed soils. The N fertilization had a significant priming effect on the turnover of soil N, which contributed 21.02%–50.47% of the total N2O emissions. During the basal fertilization/first irrigation event, straw incorporation significantly (P < 0.05) stimulated CO2 fluxes both in N-fertilized and non-N-fertilized plots; however, after the top-dressing/second irrigation event, the significant increase of CO2 fluxes induced by straw incorporation was only observed in the N-fertilized treatment. Straw incorporation interacted with N fertilization, and tended to enhance N2O emissions in the basal fertilization and lower N2O emissions in the top-dressing period. In N-fertilized plots, the seasonal N2O emissions from straw-incorporated and straw-removed treatments were similar, indicating that straw incorporation enhanced the N supply without increasing the N2O emissions. Our study highlights that there are significant benefits of straw incorporation to soil fertility improvement; however, the long-term impacts of straw incorporation on greenhouse gas emissions should be further examined

Altered SMRT levels disrupt vitamin D3 receptor signalling in prostate cancer cells.

We hypothesized that key antiproliferative target genes for the vitamin D receptor (VDR) were repressed by an epigenetic mechanism in prostate cancer cells resulting in apparent hormonal insensitivity. To explore this possibility, we examined nuclear receptor corepressor expression in a panel of nonmalignant and malignant cell lines and primary cultures, and found frequently elevated SMRT corepressor mRNA expression often associated with reduced sensitivity to 1alpha,25-dihydroxyvitamin D(3) (1alpha,25(OH)2D3). For example, PC-3 and DU-145 prostate cancer cell lines had 1.8-fold and twofold increases in SMRT mRNA relative to normal PrEC cells (P<0.05). Similarly, 10/15 primary tumour cultures (including three matched to normal cells from the same donors) had elevated SMRT mRNA levels; generally NCoR1 and Alien were not as commonly elevated. Corepressor proteins often have associated histone deacetylases (HDAC) and reflectively the antiproliferative action of 1alpha,25(OH)2D3 can be restored by cotreatment with low doses of HDAC inhibitors such as trichostatin A (TSA, 15 nM) to induce apoptosis in prostate cancer cell lines. To decipher the transcriptional events that lead to these cellular responses, we undertook gene expression studies in PC-3 cells after cotreatment of 1alpha,25(OH)2D3 plus TSA after 6 h. Examination of known VDR target genes and cDNA microarray analyses revealed cotreatment of 1alpha,25(OH)2D3 plus TSA cooperatively upregulated eight (out of 1176) genes, including MAPK-APK2 and GADD45alpha. MRNA and protein time courses and inhibitor studies confirmed these patterns of regulation. Subsequently, we knocked down SMRT levels in PC-3 cells using a small interfering RNA (siRNA) approach and found that GADD45alpha induction by 1alpha,25(OH)2D3 alone became very significantly enhanced. The same distortion of gene responsiveness, with repressed induction of GADD45alpha was found in primary tumour cultures compared and to matched peripheral zone (normal) cultures from the same donor. These data demonstrate that elevated SMRT levels are common in prostate cancer cells, resulting in suppression of target genes associated with antiproliferative action and apparent 1alpha,25(OH)2D3-insensitivity. This can be targeted therapeutically by combination treatments with HDAC inhibitors

The impacts of Hong Kong Disneyland in the Pearl River Delta

2001-2002 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

Inhibition of CK2α Down-Regulates Hedgehog/Gli Signaling Leading to a Reduction of a Stem-Like Side Population in Human Lung Cancer Cells

Protein kinase CK2 is frequently elevated in a variety of human cancers. The Hedgehog (Hh) signaling pathway has been implicated in stem cell maintenance, and its aberrant activation has been indicated in several types of cancer, including lung cancer. In this study, we show that CK2 is positively involved in Hh/Gli signaling in lung cancer cell lines A549 and H1299. First, we found a correlation between CK2α and Gli1 mRNA levels in 100 primary lung cancer tissues. Down-regulation of Gli1 expression and transcriptional activity were demonstrated after the silencing of CK2α in lung cancer cells. In addition, CK2α siRNA down-regulated the expression of Hh target genes. Furthermore, two small-molecule CK2α inhibitors led to a dose-dependent inhibition of Gli1 expression and transcriptional activity in lung cancer cells. Reversely, forced over-expression of CK2α resulted in an increase both in Gli1 expression and transcriptional activity in A549 cells. Finally, the inhibition of Hh/Gli by CK2α siRNA led to a reduction of a cancer stem cell-like side population that shows higher ABCG2 expression level. Thus, we report that the inhibition of CK2α down-regulates Hh/Gli signaling and subsequently reduces stem-like side population in human lung cancer cells

Novel SNPs polymorphism of bovine CACNA2D1 gene and their association with somatic cell score

Mastitis is a major cause of economic loss in dairy cattle. In this study, the bovine CACNA2D1 gene was taken as a candidate gene for mastitis resistance. The objective of this study was to identify single nucleotide polymorphisms (SNPs) in the bovine CACNA2D1 gene and evaluate the association of these SNPs with mastitis in cattle. Through DNA sequencing and PCR-RFLP analysis, three mutations C367400T, A496561G and G519663A were detected in the cattle CACNA2D1 gene. Altogether 240 dairy cattle of three breeds (Holstein, Simmental, and Sanhe cattle) were genotyped and allele frequencies were determined. The effects of CACNA2D1 polymorphisms on somatic cell score (SCS) were analyzed and a significant association was found between G519663A and SCS. The mean of genotype GG was significantly lower than those of genotypes AG and AA. The results of this research will be useful in further studies to determine the role of the CACNA2D1 gene in mastitis resistance and further work will be necessary to investigate whether the CACNA2D1 gene play a role in defending the host from mastitis.Key words: Association analysis, CACNA2D1 gene, dairy breeds, mastitis, somatic cell score

Induction of Cell Stress in Neurons from Transgenic Mice Expressing Yellow Fluorescent Protein: Implications for Neurodegeneration Research

Peer reviewedPublisher PD

Experimental investigation on camera calibration for 3D photogrammetric scanning of micro-features for micrometric resolution

[EN] Recently, it has been demonstrated that photogrammetry can be used for the measurement of small objects with micro-features, with good results and lower cost, compared to other established techniques such as interferometry, conoscopic holography, and 3D microscopy. Calibration is a critical step in photogrammetry and the classical pinhole camera model has been tested for magnifications lower than 2×. At higher magnification levels, because of the reduction of the depth of field (DOF), images can lead to calibration data with low reprojection errors. However, this could lead to bad results in the 3D reconstruction. With the aim of verifying the possibility of applying the camera model to magnifications higher than 2×, experiments have been conducted using reflex cameras with 60 mm macro lens, equipped with the combination of three extension tubes, corresponding to 2.06, 2.23, and 2.4 magnification levels, respectively. Experiments consisted of repeating calibration five times for each configuration and testing each calibration model, measuring two artifacts with different geometrical complexity. The calibration results have shown good repeatability of a subset of the internal calibration parameters. Despite the differences in the calibration reprojection error (RE), the quality of the photogrammetric 3D models retrieved was stable and satisfying. The experiment demonstrated the possibilities of the photogrammetric system presented, equipped to very high magnification levels, to retrieve accurate 3D reconstruction of micro-features with uncertainties of few micrometers, comparable with industry s expensive state-of-the-art technologies.Percoco, G.; Guerra, MG.; Sánchez Salmerón, AJ.; Galantucci, LM. (2017). Experimental investigation on camera calibration for 3D photogrammetric scanning of micro-features for micrometric resolution. The International Journal of Advanced Manufacturing Technology. 91(9-12):2935-2947. https://doi.org/10.1007/s00170-016-9949-6S29352947919-12Uhlmann E, Mullany B, Biermann D, Rajurkar KP, Hausotte T, Brinksmeier E (2016) Process chains for high-precision components with micro-scale features. CIRP Ann - Manuf Technol 65:549–572. doi: 10.1016/j.cirp.2016.05.001Savio E, De Chiffre L, Schmitt R (2007) Metrology of freeform shaped parts. CIRP Ann - Manuf Technol 56:810–835. doi: 10.1016/j.cirp.2007.10.008Rodríguez-martín M, Lagüela S, González-aguilera D, Rodríguez-gonzálvez P (2015) Optics & Laser Technology Procedure for quality inspection of welds based on macro-photogrammetric three-dimensional reconstruction;73:54–62Xu Z, Toncich D, Stefani S (1999) Vision-based measurement of three-dimensional geometric workpiece properties. Int J Adv Manuf Technol 15:322–331. doi: 10.1007/s001700050074Galantucci LM, Lavecchia F, Percoco G (2013) Multistack close range photogrammetry for low cost submillimeter metrology. J Comput Inf Sci Eng 13:44501. doi: 10.1115/1.4024973Maté González, M.T., Yravedra, J., González-Aguilera, D., Palomeque-González, J.F., Domínguez-Rodrigo, M. Micro-photogrammetric characterization of cut marks on bones (2015) Journal of Archaeological Science, 62, pp. 128-142. doi: 10.1016/j.jas.2015.08.006Brown DC (1971) Close-range camera calibration. Photogramm Eng 37:855–866 doi:10.1.1.14.6358Tang R, Fritsch D (2013) Correlation analysis of camera self-calibration in close range photogrammetry. Photogramm Rec 28:86–95. doi: 10.1111/phor.12009Agisoft LLC (2011) Agisoft PhotoScan User Manual :37.Jcgm JCFGIM (2008) Evaluation of measurement data—guide to the expression of uncertainty in measurement- annex B "general metrological terms"- B.2.14. Int Organ Stand Geneva ISBN 50:134. doi: 10.1373/clinchem.2003.030528Yanagi, H., Chikatsu, H. Performance evaluation of macro lens in digital close range photogrammetry (2009) Proceedings of SPIE - The International Society for Optical Engineering, 7447, art. no. 74470J, doi: 10.1117/12.825817Galantucci LM, Pesce M, Lavecchia F (2015) A stereo photogrammetry scanning methodology, for precise and accurate 3D digitization of small parts with sub-millimeter sized features. CIRP Ann - Manuf Technol 64:507–510. doi: 10.1016/j.cirp.2015.04.016Galantucci LM, Pesce M, Lavecchia F (2015) A powerful scanning methodology for 3D measurements of small parts with complex surfaces and sub millimeter-sized features, based on close range photogrammetry. Precis Eng. doi: 10.1016/j.precisioneng.2015.07.010Percoco G, Sánchez Salmerón AJ (2015) Photogrammetric measurement of 3D freeform millimetre-sized objects with micro features: an experimental validation of the close-range camera calibration model for narrow angles of view. Meas Sci Technol 26:95203. doi: 10.1088/0957-0233/26/9/095203Gallo A, Muzzupappa M, Bruno F (2014) 3D reconstruction of small sized objects from a sequence of multi-focused images. J Cult Herit 15:173–182. doi: 10.1016/j.culher.2013.04.009Stamatopoulos C, Fraser CS, Cronk S (2010) On the self-calibration of long focal length lenses. Int Arch Photogramm Remote Sens Spat Inf Sci Newcastle upon Tyne, UK 2010 XXXVIII:560–564Atkinson KB (1996) Close range photogrammetry and machine vision. Whittles PublishingLuhmann T, Fraser C, Maas HG (2016) Sensor modelling and camera calibration for close-range photogrammetry. ISPRS J Photogramm Remote Sens 115:37–46. doi: 10.1016/j.isprsjprs.2015.10.006Tsai RY (1986) An efficient and accurate camera calibration technique for 3D machine vision. Proc IEEE Conf Comput Vis Pattern Recognition 1986Ricolfe-Viala C, Sanchez-Salmeron A-J (2011) Camera calibration under optimal conditions. Opt Express 19:10769–10775. doi: 10.1364/OE.19.010769Wang L, Wang W, Shen C, Duan F (2016) A convex relaxation optimization algorithm for multi-camera calibration with 1D objects. NeurocomputingRicolfe-Viala C, Sanchez-Salmeron A. Lens distortion models evaluation. Appl Opt 2010;49:5914–5928.Percoco G, Lavecchia F, Salmerón AJS (2015) Preliminary study on the 3D digitization of millimeter scale products by means of photogrammetry. Procedia CIRP 33:257–262. doi: 10.1016/j.procir.2015.06.046Bradski G (2000) The OpenCV Library. Dr Dobb’s J Softw ToolsRicolfe-Viala C, Sanchez-Salmeron A-J (2011) Optimal conditions for camera calibration using a planar template. 2011 18th IEEE. Int Conf Image Process, IEEE 2011:853–856. doi: 10.1109/ICIP.2011.6116691Lowe DG (1999) Object recognition from local scale-invariant features. Proc Seventh IEEE Int Conf Comput Vis 2:1150–1157. doi: 10.1109/ICCV.1999.790410Triggs B, Mclauchlan P, Hartley R, Fitzgibbon A, Triggs B, Mclauchlan P, et al. (2010) Bundle adjustment—a modern synthesis to cite this version: bundle adjustment—a modern synthesisCignoni P, Callieri M, Corsini M, Dellepiane M, Ganovelli F, Ranzuglia G (2008) Meshlab: an open-source mesh processing tool. Eurographics Ital Chapter Conf 2008:129–136Besl P, McKay N (1992) A method for registration of 3-D shapes. IEEE Trans Pattern Anal Mach Intell 14:239–256. doi: 10.1109/34.12179

Hour-glass magnetic spectrum in an insulating, hole-doped antiferromagnet

Superconductivity in layered copper-oxide compounds emerges when charge carriers are added to antiferromagnetically-ordered CuO2 layers. The carriers destroy the antiferromagnetic order, but strong spin fluctuations persist throughout the superconducting phase and are intimately linked to super-conductivity. Neutron scattering measurements of spin fluctuations in hole-doped copper oxides have revealed an unusual `hour-glass' feature in the momentum-resolved magnetic spectrum, present in a wide range of superconducting and non-superconducting materials. There is no widely-accepted explanation for this feature. One possibility is that it derives from a pattern of alternating spin and charge stripes, an idea supported by measurements on stripe-ordered La1.875Ba0.125CuO4. However, many copper oxides without stripe order also exhibit an hour-glass spectrum$. Here we report the observation of an hour-glass magnetic spectrum in a hole-doped antiferromagnet from outside the family of superconducting copper oxides. Our system has stripe correlations and is an insulator, which means its magnetic dynamics can conclusively be ascribed to stripes. The results provide compelling evidence that the hour-glass spectrum in the copper-oxide superconductors arises from fluctuating stripes.Comment: 13 pages, 4 figures, to appear in Natur